Like a New York City mayor tilting at supersized sodas, several automakers have tried to forcibly wean Americans off their big, bad-for-you V8s. Six-cylinder engines are also being downsized in favour of 4s. Now, for Volvo, even a 5-cylinder engine seems to be too much.

Among Sweden’s automakers, Saab is down for the count, leaving only Volvo to fight the industry’s global giants. Volvo itself has come under the wing of Geely, the Chinese automaker, since it was cut loose by Ford in 2010 in a $1.5 billion fire sale.

In the interest of efficiency—both in fuel consumption and in business operations—the latest XC60 crossover becomes a stylish stalking horse for Volvo’s new family of 4-cylinder engines. These modular engines, gasoline and diesel alike, share components and can be built in a single money-saving factory in Sweden.

Volvo plans to bake in more efficiency by building several models on a new modular platform, starting with a redesigned, more luxurious 2015 version of its larger XC90 crossover.

But Volvo’s fans should start counting to four: The company expects these 4-cylinder engines to eventually replace every 5- and 6-cylinder engine currently offered in Volvo’s sedans, wagons and crossovers.

The 2015 XC60 T6 Drive-E gets the strongest, most technically interesting version. A 2-litre direct-injected 4 features a supercharger that squeezes out bonus power at lower engine speeds, then hands the baton to a turbocharger above roughly 3,500 rpm.

That engine may be small, but it is big for its britches with a robust 302 horsepower and 295 pound-feet of torque. It ably powers a front-drive XC60—still one of the most distinctively handsome midsize crossovers—that starts at $40,975.

For $36,675 to start, a front-drive T5 Drive-E gets a single-turbo version of the same engine with 240 horsepower and 258 pound-feet. Both Drive-E engines mate with a new 8-speed automatic transmission and an engine stop-start system.

The T6 Drive-E that I tested couldn’t match the forceful nature and sound of the force-fed 6. But it’s still plenty quick for families and late-to-work commuters. With acceleration in the same ballpark, the smaller engines show that dropping